What is a blockchain fork?
When a new feature or change to a digital currency is implemented, the blockchain of that currency undergoes a "chain split", or fork. If the change is significant enough that it renders previously created blocks incompatible with the new changes, it is referred to as a "hard fork", and the blockchain will effectively duplicate, splitting off into a new digital currency with its own tokens/coins.
For hard forks, anyone who controls the private keys of that digital currency (in a private wallet) before the fork can "split" that amount and receive the same number of new tokens at a 1:1 ratio. For example, on October 25, 2017 the Bitcoin network underwent a chain split, resulting in the creation of a new Bitcoin fork and an alternative cryptocurrency known as Bitcoin Gold (BTG). If you controlled private keys for 10 BTC at the time of this blockchain event, you were eligible to split the balance and receive an additional 10 BTG.
Because CoinJar controls the private keys of any funds stored in a CoinJar account, this is something to take into consideration leading up to a new fork.
Handling a blockchain fork
CoinJar does not typically support newly created tokens at the time of the event, and is not responsible for access to any tokens created during a chain split. Our primary focus is to ensure any funds stored in CoinJar is kept as secure as possible, and we continue to monitor such blockchain events closely to ensure all CoinJar customer funds are safe.
In the event of an upcoming blockchain event that will result in the creation of a new token, we always recommend to withdraw your funds to a privately hosted wallet if you wish to take advantage of the chain split. Although we've offered a claim period for Bitcoin Cash in the past, we cannot always guarantee a claim period for future blockchain events.
Blockchain forks do not affect digital currency balances within CoinJar accounts. Funds stored in Cash Accounts or on CoinJar Swipe are not influenced by blockchain events.
Noteworthy blockchain events
Ethereum (Istanbul)
Date expected : 08/12/19 (block 9,069,000)
Type: Ethereum network upgrade.
This Ethereum network upgrade is a hard fork, however is not contentious and no additional token will be created.
YCash
Date expected : 19/07/19 (block 570,000).
Type: Zcash hard fork.
This Zcash event will result in the creation of a new token - Ycash (YEC). CoinJar has no plans to support or distribute Ycash. Please withdraw your funds to a privately hosted wallet to claim newly created tokens.
Ethereum (Constantinople)
Original date expected (postponed): 17/01/19.
Date expected : 1/03/19.
Type: Ethereum network upgrade.
This Ethereum network upgrade is a hard fork, however is not contentious and no additional token will be created. We anticipate a downtime period of at least one hour during the upgrade.
The Lightning Network
Date: 2018 onwards.
Type: BTC development.
The CoinJar platform does not utilise the Lightning Network at this time.
Segwit
Date: 24/08/17.
Type: BTC soft fork.
The CoinJar platform utilises Segwit for incoming and outgoing bitcoin payments at this time, when P2SH addresses ('3' addresses) are used for sending and receiving.
Segwit2x
Date: 16/11/17.
Type: BTC hard fork.
Plans for Segwit2x were ultimately abandoned. Please refer to our dedicated Knowledge Base article for further details.
Bitcoin Cash (BCH)
Date: 01/08/17.
Type: BTC hard fork.
BCH remains unsupported on the CoinJar platform. A 60 day claim period was offered to affected customers who did not withdraw their funds before the date of the chain split.
Bitcoin Cash Tokens Knowledge Base article
Bitcoin Gold (BTG)
Date: 25/10/17.
Type: BTC hard fork.
BTG is not supported on the CoinJar platform. There are no plans to provide a claim system for BTG at this stage, however this may be offered in the future.
Litecoin Cash (LCC)
Date: 18/02/18.
Type: LTC hard fork.
We do not plan on supporting or providing a claim period for Litecoin Cash.